Chronic toxicity of 50 metals to Ceriodaphnia dubia.

Metals are essential elements for human life but may cause disorders when exposure is excessive. Previously, we reported on the acute toxicity of 50 metals; however, the chronic toxicity data of some metals are not available. Therefore, we conducted chronic toxicity tests to determine the effects of 50 metals on the water flea, Ceriodaphnia dubia. The IC20 of 20 metals (Be, Sc, Cr, Co, Ni, Cu, Zn, Y, Ru, Ag, Cd, In, Te, W, Os, Pt, Au, Hg, Tl and Pb) were <100 µg/L; nine metals (Al, V, As, Se, Zr, Nb, Rh, Sb and Bi) were 100 ≤ IC20 < 1000 µg/L; 16 metals (Li, Mg, K, Ti, Mn, Fe, Ga, Ge, Rb, Sr, Mo, Sn, Cs, Ba, Re and Ir) were 1000 ≤ IC20 ≤ 100 000 µg/L; and two metals (Na and Ca) were >100 000 µg/L. Three metals (Pd, Hf and Ta) did not show IC20 at the upper limit of respective aqueous solubility, and IC20 s were not obtained. The maximum test concentrations (almost aqueous solubility) of Pd, Hf and Ta were 83, 2400 and 5.3 µg/L, respectively. These data show the high correlation between our IC50 s for C. dubia and those for Dahpnia magna published previously. The IC50 s of 47 metals were not correlated with electronegativity, first ionization energy, atomic weight, atomic number, covalent radius, atomic radius or ionic radius.

Does a sum of toxic units exceeding 1 imply adverse impacts on macroinvertebrate assemblages? A field study in a northern Japanese river receiving treated mine discharge.

In ecological risk assessment, sum-of-toxic-unit approaches based on measured water quality factors such as trace metals are used to infer ecological impacts in the environment. However, it is uncertain whether the use of such approaches yields accurate risk predictions. To address this issue, we investigated and compared (1) water quality, including trace metals, and (2) benthic macroinvertebrate communities in a northern Japanese river receiving treated discharge from an abandoned mine and in a nearby reference river. As a sum-of-toxic-unit approach, we employed a cumulative criterion unit (CCU), namely, the sum of the ratios of the dissolved concentrations of a metal (Cu, Zn, Cd, or Pb) divided by the US Environmental Protection Agency hardness-adjusted environmental water quality criterion for that metal. Compared with the reference sites, at the metal-contaminated sites, the richness, abundance, and structure of macroinvertebrate communities were little affected, with CCUs of 1.7 to 7.4, suggesting that CCU values exceeding 1 do not always indicate marked adverse impacts on these metrics. Further study is still required to derive a more compelling conclusion on the generally applicable relationships between CCUs and ecological impacts on river invertebrates. This would lead to better ecological risk assessments based on sum-of-toxic-unit approaches.

Occurrence, distribution and possible sources of polychlorinated biphenyls (PCBs) in the surface water from the Bay of Bengal coast of Bangladesh.

Full profile of polychlorinated biphenyls (PCBs) in the coastal surface water from Bangladesh were analyzed by GC-MS/MS to explore the status of contamination, spatiotemporal distribution and to trace their potential sources. The total concentrations of dissolved PCBs (∑PCBs, sum of all congeners) varied from 32.17 to 160.7 ng/L and 46.45-199.4 ng/L in winter and summer, respectively, and the ranges were comparable to or higher than those recorded in the surface water from the coastal areas of India, China, Japan, Italy, Belgium and USA. The difference in the levels of PCBs between the two seasons was not statistically significant (p > 0.05). However, spatial distribution revealed that the areas with recent urbanization and industrialization (Chittagong, Cox's Bazar and Sundarbans) were more contaminated with PCBs than the unindustrialized area (Meghna Estuary). Lightly to moderately chlorinated (2-6 Cl) homologs dominated the PCB profiles. Our analyses (congener profile and homolog composition) elucidated that the past and on-going use of PCB-containing equipment (e.g. capacitors and transformers) as well as the anthropogenic activities such as urban developments, commercial and industrial establishments (e.g. ship breaking and port activities) might be the potential sources of PCB emission in Bangladesh. A set of congeners based on their detection frequencies and abundance were identified and categorized as potential environmental marker PCBs, which can be used for the future selective monitoring studies regarding reasonable limitations on full congener assessment. According to the existing national and international water quality guidelines/standards, PCB concentrations recorded in this study could potentially cause biological damage. Essentially, the findings of this first comprehensive report on the PCB contamination in the surface water in Bangladesh may provide a reference to future studies of these compounds in the Bay of Bengal.

Distribution, Source Apportionment, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in the Surficial Sediments from the Coastal Areas of Bangladesh.

The surficial sediments were collected in winter and summer (2015) from the coastal areas of Bangladesh and analyzed for 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs). The total concentration of PAHs (∑PAHs) were 349.8-11,058.8 and 199.9-17,089.1 ng/g dry weight (dw) in winter and summer, respectively. Sediements from the areas with recent urbanization and industrialization (Chittagong, Cox's Bazar, and Sundarbans) were more contaminated with PAHs than the unindustrialized area (Meghna Estuary). The concentrations of ∑PAHs were slightly higher in summer than those in winter, but the seasonal variations were not statistically significant (p > 0.05). Molecular ratios suggested mixed sources of PAHs in the Bangladeshi coastal areas with a slight imposition of pyrolytic inputs closely related to shipping and fishing activities as well as industrial and municipal sewage discharge. According to ecological risk assessment, the measured levels of sedimentary PAHs exceeded some of the existing national and international environmental quality guidelines/standards, and thus might cause acute biological damage in the studied areas of the Bay of Bengal coast of Bangladesh.

Distribution of polycyclic aromatic hydrocarbons (PAHs) in commonly consumed seafood from coastal areas of Bangladesh and associated human health implications.

Levels, distribution, possible sources and potential risks of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) were investigated comprehensively in frequently consumed seafood species collected from the coastal areas of Bangladesh. Samples were collected in winter and summer, 2015. The total concentration of PAHs (∑PAHs) in the examined seafood was 184.5-2806.6 ng/g wet weight (ww) in winter and 117.9-4216.8 ng/g ww in summer, respectively. The levels of ∑PAHs were comparable to or higher than those reported from other coastal areas. Seasonal variation was not significant for the majority of the monitored PAHs. Spatial distribution revealed that the seafood collected from areas with recent urbanization and industrialization (Chittagong, Cox's Bazar and Sundarbans) was more contaminated with PAHs than those from the unindustrialized area (Meghna Estuary). Low-molecular-weight isomers dominated the PAH composition. Molecular ratios suggested the abundance of mixed sources of PAHs in the Bangladeshi coastal areas with a slight imposition toward the petrogenic origin. A preliminary evaluation of human health risk indicated that the dietary PAH exposure from consumption of Bangladeshi seafood would certainly induce adverse health effects. This finding suggests the need to enhance risk management regarding seafood consumption through public advisory in Bangladesh.

Occurrence and ecological risk of pharmaceuticals in river surface water of Bangladesh.

Pharmaceutical contamination in the aquatic environment is a global issue that affects aquatic animals, micro-organisms and human health. The occurrence and preliminary ecological risk of 12 (11 antibiotics and 1 antiepileptic drug) pharmaceuticals were investigated for the first time in the surface water of the old Brahmaputra River, where open-water-fed aquaculture activities are being practiced in Bangladesh. The pharmaceuticals were quantified by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), operated with positive electrospray ionization (ESI+) and a multiple reaction monitoring (MRM) mode. Nine pharmaceuticals were detected in the river surface water, whereas three were below the limit of detection (LOD). Metronidazole was detected in all the samples with concentrations ranging from 0.05 to 13.51 ng L-1. Trimethoprim had the second highest frequency of detection (95%) with the highest concentration (17.20 ng L-1). The ranges of concentration and detection frequency of sulfonamides and macrolides were

Chemical speciation of trace metals in the industrial sludge of Dhaka City, Bangladesh.

The objective of this study was to assess total concentration and chemical fractionation of trace metals in the industrial wastewater and sludge collected from seven different types of industries in Dhaka City, Bangladesh. The sludge from industries is either dumped on landfills or reused as secondary resources in order to preserve natural resources. Metals were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The ranges of Cr, Ni, Cu, As, Cd, and Pb in the sludges were 1.4-9,470, 4.8-994, 12.8-444, 2.2-224, 1.9-46.0 and 1.3-87.0 mg/kg, respectively. As a whole, the average concentrations of trace metals in samples were in the decreasing order of Cr > Ni > Cu > As > Pb > Cd. The results of the Community Bureau of Reference (BCR) sequential extraction showed that the studied metals were predominantly associated with the residual fraction followed by the oxidizable fraction. The study revealed that the mobile fractions of trace metals are poorly predictable from the total content, and bioavailability of all fractions of elements tends to decrease.

Organophosphate flame retardants in the indoor air and dust in cars in Japan.

The concentrations of organophosphate flame retardants (OPFRs) in the indoor air and dust were measured in 25 unoccupied cars in Japan. In the indoor air of the cars, most OPFRs were neither detected nor found at a concentration lower than the method quantification limit. The highest concentration (1500 ng m-3) was obtained for tris(1-chloro-2-propyl) phosphate (TCIPP). By contrast, many OPFRs were detected in the dust samples collected from the interior of the cars. TCIPP and tris(2-ethylhexyl) phosphate (TEHP) were present at the highest concentrations at 390 µg g-1 (in dust from car seats) and 640 µg g-1 (in dust from car floor mats), respectively. The highest median concentrations (35 µg g-1 for car seats, 53 µg g-1 for car floor mats) were obtained for tris(2-butoxyethyl) phosphate (TBOEP). According to the results of our exposure assessment, the typical exposures to OPFRs via inhalation in car cabins ranged from 9.0×10-4 to 7.8×10-1 ng kg-bw-1 day-1. The typical exposures to OPFRs via dust ingestion ranged from 9.2×10-4 to 8.8×10-1 ng kg-bw-1 day-1. We compared these results with the ref-erence doses for OPFRs and found that, based on cur-rent information about the toxicities of OPFRs, exposure to OPFRs in car cabins via inhalation and dust ingestion is unlikely to have adverse human health effects.

Assessing bioavailability levels of metals in effluent-affected rivers: effect of Fe(III) and chelating agents on the distribution of metal speciation.

To assess the effects of Fe(III) and anthropogenic ligands on the bioavailability of Ni, Cu, Zn, and Pb, concentrations of bioavailable metals were measured by the DGT (diffusive gradients in thin films) method in some urban rivers, and were compared with concentrations calculated by a chemical equilibrium model (WHAM 7.0). Assuming that dissolved Fe(III) (<0.45 µm membrane filtered) was in equilibrium with colloidal iron oxide, the WHAM 7.0 model estimated that bioavailable concentrations of Ni, Cu, and Zn were slightly higher than the corresponding values estimated assuming that dissolved Fe(III) was absent. In contrast, lower levels of free Pb were predicted by the WHAM 7.0 model when dissolved Fe(III) was included. Estimates showed that most of the dissolved Pb was present as colloidal iron-Pb complex. Ethylene-diamine-tetra-acetic acid (EDTA) concentrations at sampling sites were predicted from the relationship between EDTA and the calculated bioavailable concentration of Zn. When both colloidal iron and predicted EDTA concentrations were included in the WHAM 7.0 calculations, dissolved metals showed a strong tendency to form EDTA complexes, in the order Ni > Cu > Zn > Pb. With the inclusion of EDTA, bioavailable concentrations of Ni, Cu, and Zn predicted by WHAM 7.0 were different from those predicted considering only humic substances and colloidal iron.

Does the Choice of NOEC or EC10 Affect the Hazardous Concentration for 5% of the Species?

We evaluated if the choice of no observed effect concentration (NOEC) or a 10% effect concentration (EC10) affects the hazardous concentrations for 5% of the species (HC5s) estimated from species sensitivity distributions (SSDs). By reviewing available literature reporting NOECs and reanalyzing original toxicity data to estimate EC10s, we developed two SSDs for five chemicals (zinc, lead, nonylphenol, 3,4-dichlorobenzenamine, and lindane) based separately on 9-19 EC10s and NOECs. On average, point estimates of HC5s based on EC10s were 1.2 (range of 0.6-1.9) times higher than those based on NOECs. However, both EC10-based and NOEC-based HC5s estimated for five substances were on the same order of magnitude, and their 95% confidence intervals overlapped considerably. Thus, although EC10 was chosen as a representative of ECx in this study, our results suggest that the choice of ECx (e.g., EC5, EC10, or EC20) or NOEC does not largely affect the resulting HC5s. Therefore, use of NOECs would be acceptable particularly in regulatory contexts, although the NOEC has important shortcomings and should be used with caution.

Reduction in toxicity of wastewater from three wastewater treatment plants to alga (Scenedesmus obliquus) in northeast China.

The toxicity of municipal wastewater to the receiving water bodies is still unknown, due to the lack of regulated toxicity based index for wastewater discharge in China. Our study aims at gaining insight into the acute toxic effects of local municipal wastewater on alga, Scenedesmus obliquus. Four endpoints, i.e. cell density, chlorophyll-A concentration, superoxide dismutase (SOD) activity and cell membrane integrity, of alga were analyzed to characterize the acute toxicity effects of wastewater from municipal wastewater treatment plants (WWTPs) with different treatment techniques: sequencing batch reactor (SBR), Linpor and conventional activated sludge. Influent and effluent from each treatment stage in these three WWTPs were sampled and evaluated for their acute toxicity. Our results showed that all three techniques can completely affect the algal chlorophyll-A synthesis stimulation effects of influent; the algal cell growth stimulation effect was only completely removed by the secondary treatment process in conventional activated sludge technique; toxic effects on cell membrane integrity of two influents from WWTPs with SBR and conventional activated sludge techniques were completely removed; the acute toxicity on SOD activity was partially reduced in SBR and conventional activated sludge techniques while not significantly reduced by Linpor system. As to the disinfection unit, NaClO disinfection enhanced wastewater toxicity dramatically while UV radiation had no remarkable influence on wastewater toxicity. Our results illustrated that SOD activity and chlorophyll-A synthesis were relatively sensitive to municipal wastewater toxicity. Our results would aid to understand the acute toxicity of municipal wastewater, as well as the toxicity removal by currently utilized treatment techniques in China.

Reduction in toxicity of coking wastewater to aquatic organisms by vertical tubular biological reactor.

We conducted a battery of toxicity tests using photo bacterium, algae, crustacean and fish to evaluate acute toxicity profile of coking wastewater, and to evaluate the performance of a novel wastewater treatment process, vertical tubular biological reactor (VTBR), in the removal of toxicity and certain chemical pollutants. A laboratory scale VTBR system was set up to treat industrial coking wastewater, and investigated both chemicals removal efficiency and acute bio-toxicity to aquatic organisms. The results showed that chemical oxygen demand (COD) and phenol reductions by VTBR were approximately 93% and 100%, respectively. VTBR also reduced the acute toxicity of coking wastewater significantly: Toxicity Unit (TU) decreased from 21.2 to 0.4 for Photobacterium phosphoreum, from 9.5 to 0.6 for Isochrysis galbana, from 31.9 to 1.3 for Daphnia magna, and from 30.0 to nearly 0 for Danio rerio. VTBR is an efficient treatment method for the removal of chemical pollutants and acute bio-toxicity from coking wastewater.

Metal speciation in sediment and their bioaccumulation in fish species of three urban rivers in Bangladesh.

Six trace metals (chromium [Cr], nickel [Ni], copper [Cu], arsenic [As], cadmium [Cd] and lead [Pb]) were measured in sediments and soft tissues of three commonly consumed fish species (Channa punctatus, Heteropneustes fossilis, and Trichogaster fasciata) collected from three urban rivers around Dhaka City, Bangladesh. The abundance of total metals in sediments varied in the decreasing order of Cr > Ni > Pb > Cu > As > Cd. Sequential extraction tests showed that the studied metals were predominantly associated with the residual fraction followed by the organically bound phase. The range of metal concentration in fish species were as follows: Cr (0.75-4.8), Ni (0.14-3.1), Cu (1.1-7.2), As (0.091-0.53), Cd (0.008-0.13), and Pb (0.052-2.7 mg/kg wet weight [ww]). The rank of biota-sediment accumulation factor for fish species were in the descending order of Cu > As > Pb > Ni > Cr > Cd. Metal concentrations in fish exceeded the international permissible standards suggesting that these species are not safe for human consumption.

Comparison study on observed and estimated concentrations of perfluorooctane sulfonate using a fate model in Tokyo Bay of Japan.

Perfluorooctane sulfonate (PFOS) was quantified in seawater and sediment samples collected from Tokyo Bay, Japan, ranging from 2.0 to 7.3 ng/L for surface seawater, 2.2 to 5.7 ng/L for intermediate seawater, 1.5 to 5.7 ng/L for bottom seawater, and 0.3 to 0.9 ng/g dry wt. for sediment. In addition, a 3-D chemical fate prediction model (National Institute of Advanced Industrial Science and Technology - Risk Assessment Model: AIST-RAM) has been applied to determine the accuracy of estimating PFOS in Tokyo Bay. A decreasing trend of PFOS from the northwestern part (i.e., the closed-off section of Tokyo Bay) to the mouth of the bay was observed, and the trend obtained from the actual surveys in this study was accurately represented by simulation with appropriate input parameters for AIST-RAM. From the comparison of observed concentrations with estimated concentrations, AIST-RAM showed a high degree of accuracy in estimating the concentrations of PFOS in seawater, whereas the estimations of PFOS concentrations in sediment had a relatively larger margin of error than those in seawater. However, our results indicate that AIST-RAM allows estimation of PFOS concentrations in seawater and sediment in Tokyo Bay with satisfactory accuracy.

Trace metals in soil and vegetables and associated health risk assessment.

The objective of this study was to assess the contamination level of trace metals in soil and vegetables and health risk to the urban population in Bangladesh. The range of Cr, Ni, Cu, As, Cd, and Pb in agricultural soils was 158-1160, 104-443, 157-519, 41-93, 3.9-13, and 84-574 mg/kg, respectively. Sequential extraction tests revealed that the studied metals were predominantly associated with the residual fraction, followed by the organically bound phase. Concerning Cu, Ni, Cd, and Pb in vegetables, more than 50 % samples exceeded the FAO/WHO recommended permissible limits. Considering the transfer of metals from soil to vegetables, Cu and Cd exhibited higher transfer factor (TF) values than the other metals. Target hazard quotient (THQ) for individual metal was below 1, suggesting that people would not experience significant health hazards if they ingest a single metal from vegetables. However, total metal THQ signifies the potential non-carcinogenic health hazard to the highly exposed consumers. The carcinogenic risk (TR) of As (1.9 × 10(-4)) and Pb (2.3 × 10(-5)) through consumption of vegetables were higher than the USEPA threshold level (10(-6)), indicating potential cancer risks.

Evaluation of the potentials of rice varieties and water management practices for reducing human health risks associated with polluted river water irrigated rice in Bangladesh.

The consumption of arsenic and trace-metal-contaminated rice is a human health concern worldwide, particularly in Bangladesh. In this study, the effects of rice varieties and water management practices on the concentrations of arsenic and trace metals in rice grains were investigated to reduce human health risks related to rice consumption. In addition, the performance of risk reduction using the optimum combination of rice variety and water management practices was quantitatively assessed using Monte Carlo simulation, in which non-carcinogenic and carcinogenic risk distributions under the status quo and the optimum combination were compared. The experimental results revealed that Dular and BRRI dhan45 (rice varieties) cultivated under alternate wetting and drying (AWD) and continuous flooding (CF) conditions showed the lowest hazard quotient (HQ) values for copper, cadmium, and arsenic and the lowest target cancer risk (TR) for arsenic. In Dular and BRRI dhan45 (AWD and CF) varieties, the proportion of the population for which HQs exceeded 1.0 (the reference value) tended to decrease (except for arsenic), compared with populations for which the rice varieties and water management practices were not specified. These results suggest that the use of optimum combinations of rice varieties and water management practices could reduce non-carcinogenic and carcinogenic risks associated with arsenic and trace metals uptake via rice grain consumption by the Bangladeshi people.

Atmospheric polychlorinated naphthalenes in Ghana.

A nationwide monitoring of atmospheric POPs (persistent organic pollutants) was conducted in Ghana between May and July 2010, applying polyurethane foam (PUF) disk passive air samplers (PAS). Reported here are preliminary findings on PCNs, an industrial organic contaminant currently under review for possible listing under the global chemical treaty. The present results constitute the first set of nationwide data on air PCNs from a West African country. Contrary to expectation, air PCNs levels were quite high in Ghana, at an average of 49 ± 5.4 pg/m(3). The coastal (southern) zone of Ghana appeared the most impacted, with crude open burning of waste, industrial emissions, and the harbor environment identified among possible emission factors. Tri- and tetra-CNs (the lowly chlorinated homologues) predominated in the atmosphere, altogether constituting approximately 90% of total PCN homologues composition. Increased volatilization under tropical conditions was presumed a key factor that contributed to this high atmospheric input of lowly chlorinated homologues. We further observed a significant level of fractionation of PCN homologues across the breadth of the country. The percentage composition of the lowly chlorinated homologues increased northwards, probably because of their transportation in the direction of prevailing winds. From congener profile analysis, PCN-45/36 is proposed as a possible source marker for emissions preempted by uncontrolled waste burning activities. Dioxin-like toxicity of air PCNs in Ghana was estimated to range 0.49-5.6 fg TEQ/m(3). This study brought to the fore the emerging problems of nonagricultural organohalogens that covertly might be confronting the environment in African nations like Ghana.

Sources and distribution of hexabromocyclododecanes (HBCDs) in Japanese river sediment.

The distribution of hexabromocyclododecane (HBCD) in the sediment of three Japanese rivers with different characteristics (i.e., population and potential source in the catchment) was investigated and compared with the results estimated using a multimedia fate model (ChemCAN). High concentrations of HBCD in sediments in the range of 134-2060 ng g(-1) were found in a river receiving textile wastewater. This contrasted with the much lower concentrations (0.8-4.8 ng g(-1)) observed for an urban river (with a surrounding population of 1.8 million). The medians of observed HBCD concentrations in each river were close to those estimated based on the assumed input source (e.g., 1810 ng g(-1) for the observed median concentration, and 1436 ng g(-1) for the estimation, in the Kuzuryu River). These results demonstrated the importance of considering source contributions of HBCD, including both industrial and consumer sources, to aquatic environments, for reliable risk management.

Environmental impact assessment of chlorine in liquid crystal display glass (LCDG) based on material flow analysis.

Liquid crystal display glass (LCDG) may contain chlorine in trace amounts to attain some of its special properties. LCDG is primarily manufactured by glass companies, which then supply the electronic industry for utilization in the manufacture of items such as televisions, computer monitors, etc. In order to be seen as environmentally friendly, some electronic companies that utilize LCDG request that glass companies eliminate halogens such as chlorine from LCDG. The issue of halogens in products is often associated with dioxin-like problems. By using halogen-free LCDG in their manufacturing process, electronic companies aim to enhance their eco-friendly branding. Nevertheless, the real gains in terms of environmental improvement are yet to be assessed. In this study, we discussed the effectiveness of reducing or eliminating chlorine in electrical and electronic products on a scientific basis, by carrying out a quantitative assessment of cancer risk posed by potential emissions of dioxins when discarded LCDG is incinerated. The results indicate that the maximum increase of individual lifetime cancer risk is 3.2 × 10(-10). This level of cancer risk is negligible. Consequently, we suggest that there is no need to introduce stricter standards for chlorine content in LCDG, from the viewpoint of potential dioxin formation.

Assessment of the sources of suspended particulate matter aerosol using US EPA PMF 3.0.

The main purpose of this paper was to carry out a source apportionment of suspended particulate matter (SPM) samples using positive matrix factorization procedure. The central and local Government of Japan introduced strict emission regulations in 2002/10 and 2003/10, respectively, in curbing SPM pollution from major metropolitans. This paper also highlighted the impact of the measures taken by the central and local Government of Japan on the reduction of SPM and the contributions of sources. SPM samples were collected for 6 years starting from 1999 to 2005 at two sites, i.e., site A (urban) and site B (suburban) of Yokohama, Japan. Microwave digestion and inductively coupled plasma-mass spectroscopy (ICP-MS) were employed to measure Mg, Al, Ca, V, Cr, Mn, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Pb and Bi, while water soluble ions (Na(+), NH4⁺, K(+), Ca(2+), Mg(2+), Cl(-), NO3⁻ and SO4²â» as well as carbonaceous mass (EC and OC) were analyzed using ion chromatograph and CHN analyzer, respectively. The sources identified at two sites were automobile, soil dust, marine aerosol, mixed sources, and secondarily formed aerosol. Also, source quantification was performed. Automobile and soil dust were striking contributors at site A. Automobile and soil dust of SPM aerosol might be produced from local origin at current study areas. Besides, Asian dust had an impact on high concentrations of SPM aerosol in some certain period of the year due to the outflows of East Asian emission. In contrast, secondary aerosol in the form of sulfate and ammonium as well as mixed sources (coal, long-transported Cs, and other unknown sources) were remarkable at site B. Stationary/industrial combustion has apparently more impact on the release of SPM components at site B than A. Automobile regulations in 2002 and 2003, respectively, resulted in reduction of SPM by 28% for site A and 16% for site B. There was also net reduction of automobile contribution at both sites due to the above measures being implemented.